On Tue, 2018-11-20 at 14:41 +0200, Jarkko Sakkinen wrote: > On Tue, Nov 20, 2018 at 01:10:49PM +0200, Jarkko Sakkinen wrote: > > This is basically rewrite of TPM genie paper with extras. Maybe > > just shorten it to include the proposed architecture and point to > > the TPM Genie paper (which is not in the references at all ATM). > > > > The way I see it the data validation is way more important than > > protecting against physical interposer to be frank. > > > > The attack scenario would require to open the damn device. For > > laptop that would leave physical marks (i.e. evil maid). In a data > > center with armed guards I would wish you good luck accomplishing > > it. It is not anything like sticking a USB stick and run. > > > > We can take a fix into Linux with a clean implementation but it > > needs to be an opt-in feature because not all users will want to > > use it. > > Someone (might have been either Mimi or David Howells but cannot > recall) correctly pointed out at LSS 2018 that you could just as > easily spy and corrupt RAM if you have a time window to perform this > type of attack. Not using the simple plug in on the TPM bus, you can't. The point is basically the difference in the technology: the interposer is a simple, easy to construct, plugin; a RAM spy is a huge JTAG thing that would be hard even to fit into a modern thin laptop, let alone extremely difficult to build. James
